Friction shock-absorbing mechanism



Feb. 2 1926. 1,571,699

A. M. BRENNE FRICTION SHOCK ABSQRB'ING MECHANISM y Kw4@ A. M. BRENNEFRICTION SHOCK ABSORBING MECHANISM Feb. "2 1926.

2 Sheets-Sheet 2 Filed Dec. 26, A1922 Patented F eb. 2, i925.

UNITED stares ARILD M. BRENNE, OF CHICAGO, LLINGS,

aSSilnl-ltTOiE-b, BY IE'IESNE ASSIGNMENTS, TO

W. H. MINER, l'NC., A CORORATON OF DELAWARE.

FRICTION SHOCK-ABSOIEt-BNG MECHANJSM.

Application filed December To ZZ 'ic/1.0711, it may concer/2..'

Be it known that l', linien lill. BnnNNn, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and ,citate ofIllinois, have invented a certain new and useful Improvement in FrictionShocl- ,-Xbsorbing lilechanisms, of which the following is a. full,clear, concise, and exact description, reference being had to theaccompanying drawings, forming a part of this specification.

This invention relates to improvements in friction shock absorbingmechanisms.v

One object of the invention is to provide a friction shock absorbingmechanism especially adapted for railway draft rigging-S, wherein areobtained high capacity and easy release.

Another object of the invention is to provide, in a mechanism of thecharacter indicated, means automatically operable, in compensating' forwear, to gradually increase the effective wedging angle so that loss incapacity otherwise resulting from setting of the springs and loss ininitial compression of the springs, is thus offset o1 counterbalanced.

A still further object of the invention is to provide, in a mechanismofthe character indicated, a wedging system of relatively keen anglecharacter at the initiation of a compression stroke, which wedgingsystem gradually changes, during the progress of the compression stroke,to a wedge system having a blnnter effective wedging angle so that, inobtaining the desired total capacity, a higher initial frictionalresistance may be employed in the compression stroke with a resultinglesser ultimate peak load, thereby reducing the ultimate shockstransmitted to the car underframe.

Other objects of the invention will more clearly appear from thedescription and claims hereinafter following.

[n the drawings forming a part of this specification, Figure l is ahorizontal longitudinal sectional view of a portion of a railway draftrigging showing my improvements in connection therewith. Figure 2l is afront end elevational view of the shock absorbing mechanism proper.Figure 3 is a broken vertical longitudinal sectional view correspondingto the section line 3--3 of 26, 1922. Serial No. 608,825.

draw bar is indicated at 13, the same being operatively associated withthe shock ahsorbing mechanism proper by a hooded cast yoke 14 withinwhich is disposedthe shock absorbing mechanism proper and a frontfollower' l5. The yoke and parts therewitht in are supported inoperative position by a detachable saddle plate 16.

rlhe improved shock absorbing mechanism proper, as shown, comprises acombined friction shell and spring cage casting A;V

four main spring resistances li-B; a fifth spring resistance C; a. pairof friction shoes D-D; a pair of `wedge elements E-E; a spring cap F; apair of compensating wedge elements (Si-Gf; and a combined retainer andfulcrum pin l-ll..

The casting A, as shown, is of rectangular cross section having top andbottom walls lil-17, integral rear' vertical wall 18 acting as the rearfollower of the mechanism and two side walls 19-19, the latter beingmade relatively shortso as to leave the major portion of the sides ofthe casting A open to permit of the insertion and removal of certain ofthe parts. The inner faces of the side walls 19 are preferably recessedas indicated at 2O to accommodate special wear resisting blocks orliners 21-21, each of the latter being provided on its inner side with alongitudinally extending flat friction surface 522, said surfacesconverging inwardly of the shell. y

The two shoes l) are of like construction, each being in the form of ankelongated member having` an outer flat friction surface 23 cooperablewith a shell friction surface 2,2. 0n its inner side, each shoe D isprovided with a concave bearing surface 24, y

the latter corresponding to the section ofl a cylindrical surface, thecenter ofwhich isv located in a radius Vperpendicular to the wedge faceof one of the wedge elements E hereinafter described. At their innerends, the shoes l) bear upon a spring follow-er 25, which in turn bearsupon the four main lbetween -the two wedge faces 27.

spring resistances B, the latter being'uniformly arranged in the fourcorners of the spring cage portion of the castingV A.

The two wedge elements E are of like construction, each having a frontbearing face y26 engaging the inner side of the front inain E and thusadapting,r the latter to rock orr tilt with respect to each other andwith respect to other parts of the mechanism. Stated in another manner,the wedge of the friction unit may be said to consist of two rockerelements having their wedge faces relatively adjustable, for thepurposes here- Vinafter described.

Interposed between each wedge element E and the corresponding shoe isone of the elements G, the latter being` segmental in cross section andhaving' each an outer convex surface 29 cooperating with thecorresponding concave surface 24h Cn the side adjacent the axis of themechanism, each element G- is provided with a flat face 30 cooperablewithv the corresponding wedge face 27.

The centrally disposed spring' C is made longer than the other springs Band is ei:- tended through a central aperture 3l in the foll-o-wer 25.To the forward end of the spring C is applied the spring cap F which hasa forwardly projecting section 32 of wedge-shape, thus providing twowedge faces The latter cooperate with curved bearing faces 34 soarranged that relative adjustment between the element F and the wedgeelements E is permitted.

The operation of the mechanism, assuming a compression stroke in buff,is as follows. As the pressure is applied to the follower 15 and fromthe latter'transmitted to the wedge elements E, the bearing elements Gand shoes D will be forced inwardly of the shell. The initial effectivewedging' angle will correspond to the included angle As the elements areforced inwardly of the shell, the shoes D will approach each otherlaterally, due tothe tapered friction shell surfaces 22, This relativelateral approach of the two shoes D is compensated for by rocking of thetwo elements E upon the fulcrum pin H in such manner thatthe inner endsof the elements E will laterally approach cach other, thereby squeezing'out the wedge shaped spring cap F. It will be obvious that this actionis accommodated by reason of the cooperating concaveand convex bearinglsurface-s on the shoes D and bearing members G, respectively. As thisaction occurs, it is apparent that the included angle between the wedgefaces 27 will gradually increase, thus producing a. wedging system ofblunter angle effect than was present at the initiation of thecompression stroke. iVith this construction, in obtaining' apredetermined total capacity for the mechanism, l am enabled to use acomparatively keen angle to obtain high capacity at the initiation ofthe stroke with a consequently dccreased nltimate or peak load at theend of the stroke. In carrying` out my invention, the included anglebetween the faces 33-33 oitl the spring cap will be so chosen that ahigh lateral pressure will be maintained between the inner ends of thewedge elements E, but yet of sufficient bluntness as to permit thespring'cap being` squeezed out at a predetermined lateral pressurewithin the Velastic limit of the shell. Stated in another manner, if theincluded angle between the wedge faces 33 of the spring cap F were madeof such acuteness that the cap could not be squeezed out as thecompression stroke takes place to permit collapse of the rocker wedge,the shell'mig'ht be expande-d beyond its elastic limit. ln actualpractice, the included angle between the wedge faces Btl-3?) willapproximate about 'el-00 i Another important feature of the inventionresulting' from the construction.shown and described, resides in thefollowing'. As wear occurs on the shell and shoe friction surfaces, theshoes D will separate laterally gradually as the mechanism vremains inservice. rlhis allows the inner end of the rocker wedge to expandslightly, the action beine' induced by pressure derived from the springcap YF. it being understood that the spring C is placed in the gearunder initial compression. rthis action on the roclie: wec le'eobviously tends to decrease the ineluded angle between the wedge faces27--27, thereby increasing the effective wedging action of the wedgesysten'i. This has the leffect of compensating for loss in capacitvwhich might otherwise arise by reason of the springs taking' some set.and also becauseI of the reduced initial capacity in the spring' C asthe latter gradually lcngthens, due to the forward movement of thespring cap F in taking up wear.

Dui-ine; the compression stroke, the friction shell will be expanded sothat, upon removal of the actuating' force, the energy stored up in theshell will re-act with forces directed inwardly toward the asis of tha:inechanisi'n. These forces will be transmit ted to the wedge El.causing; a sligh further collapse thereof at theinitiation oi therelease action, thus increasing the blunt Uri llO

ness of the included angle between the wedge faces 27-27 andfacilitating the collapse of the friction unit.

The pin H; in addition to performing its function as a fulcrum for thewedge rocker elements E, also serves to retain the parts in assen'ibledposition. By referring to Fig-- ure 3, it will be noted that the pin Hhas its ends working in `longitudinal recesses 5() provided on the innerside of the top and bottom walls of. the castings A, said pin Ilf being'limited in its forwai'd movement with respect to the casting. Due to thenature of the engagement'between the pin I-I. and the roel-rer elementsE; the latter will also be limited in their outward movement withresrect to the casting A, and the same will be true of the remainingmovable elements. The pin H may be introduced in ithe casting through asuitable opening 5l in the top wall thereof.

I have herein shown and described what I now consider the preferredmannerof .arrying out my invention, but the same is merely illustrativeand I contemplate all changes and modifications that come within thescope of the claims appended hereto.

I cla-im:

l. In a friction shock absorbing mechanism, the combination with afriction shell; of a spring resistance; friction shoes coop erable withsaid shell; a collapsible pressure transmitting wedge including rockerparts; and angularly adjustable bearing elements between said parts ofsaid wedge and said shoes.

Q. In a fi'iction shock absorbing mechanism. the combination with a.friction shell having intei'ior friction surfaces converged inwardly ofthe shell; of a spring resistance; friction shoes cooper-able with saidshell; a collapsible pressurre-'transmitting wedge ii'icludingi'relatively rocking spreading members; and fulcruin-acting adjustablebearing elements between said rocking meinbers of said wedge and theshoes.

3. In a friction shock absorbing mecha-- nisi'n; the combination with afriction shell; of a spring' resistance; friction shoes cooperable withsaid shell: a wedge system cooperable witli said shoes. said wedgesystem havingan original predetermined effective wedgiiigangle; andmeans interposed between said shoe and wedge system whereby vthe partsof said wedge system are adapted to automatically adjust themselvesrelatively to each other and relatively to the shoes as wear occurs onthe friction surfaces of the shoes and shell, allowing` the shoes toseparate laterally, to thereby produce a gradually decreasing edectivewedgiiig angle.

4. In a friction shock absorbing mecha.- nism, the con'il'iination witha friction shell having interior friction surfaces converged inwardly ofthe shell; of a spring resist.- ance; friction shoes cooperable withsaid shell; a wedging sys-tem cooperable with the slices, said wedgesystem having an initial predetermined effective wedge angle at thebeginning of a compression sti'oke; and adjustable elements coactingwith said shoes and wedge system whereby the parts of said wedge systemai'e adapted to automatically adjust themselves relatively to eachotherI and relatively to the slices, during` a coinpression stroke, toincrease the effective wedging angle.

In a friction shock absorbing mechanisni, the combination with africtionshell having interior friction surfaces converged inwardly of the shell;of a spring resistance; friction shoes coopei'able with` the shell, saidshoes having adjustable means thereon presenting wedge faces; and :iwedgiiig system consisting of a plurality of parts cooperable with saidshoes; said wedging system having' an original effective predeterminedwedging angle automaticallyin creasing by relative movement of the partsof the wedge system as wear occurs on the shell and shoes, the parts ofsaid wedge system also automatically adjusting themselves relatively t-oeach other and the shoes during a compression stroke in a manner toincrease the wedge angle.

6. In a friction shock absorbing' mechanism7 the combination with afriction shell; of a spring;` resistance; friction shoes coopei'ablewith said shell; a wedge .system cooperable with said shoes` said wedgesystem having an original predetermined effective wedging angle; andangularly adjustable means between said wedge system and shoes wherebvthe parts ofl said wedge system are adapted to automatically adjustthemselves relatively to each other and relatively to the shoes as wearoccurs on the friction surfaces of the shoes and shell, allowing theshoes to separate laterally, to thereby produce a gradually. increasingeffective wedgiiig angle, said wedge system including two elementspivot-ally mounted with respect to each other.

7. In a friction shock absorbing mechaiiisni, the combination with afriction shell having' interior friction surfaces converged inwardly ofthe shell; of a spring resistance: frictionshoes cooperable with saidshell, said shoes having;` angularly adjustable means thereon; and awedging system cooperable with angularly adjustable means on the shoes.said wedge system having an initial predetermined effective wedge angleat the beginning of a compression stroke, the parts of said wedge systemautomatically adjusting themselves relativelv to each other andrelatively to the shoes. during a conipression stroke, to increase theeffective wedgmg angle, said wedge system including two elementspivotally mountedv with respect fto each other.

8. In a friction shock. absorbing mechanism, the combination with afriction shell having interior friction surfaces converged inwardly ofthe shell; of a spring resistance; friction shoes cooperable with theshell; a wedging system consisting of a plurality of parts cooperablewith said shoes, said wedge system having an original effectivepredetermined wedging angle; means coacting with said wedge system forautomatically decreasing the lwedging angle by relative movementof theparts of the wedge system as wear occurs on the shell and shoes; andangularly adjustable means between said wedge system and shoes wherebythe parts of said wedge system also automaticallyV adjust themselves.relatively to each other and the shoes during a compression stroke in amanner to increase the effective wedging angle; said wedge systemincluding two wedgek elements pivotally mounted with respect to eachother.

v9. In a friction shoclcabso-rbing mechanism, the combination with afriction shell having interior friction surfaces converged inwardly oftheshell; friction shoes cooperable with the shell; a pair of relatively:n

fulcrumed pressure transmitting wedge elements; a follower coacting withsaid elements; means for yieldingly resisting movement lof said followerand shoes; and bearing elements interposed between said Wedge elementsand the shoes, said bearing elements and the shoes having cooperatingcurved bearing faces and said bearing elements and the wedge elementshaving flat engaging faces. v

l0. In a friction shock absorbing mechanism, the vcombination withafriction shell having interior friction surfaces converged inwardly ofthe. shell; of a spring resistance; friction shoes cooperable with theshell; a pair of rocker4 pressure transmitting elements; spreading meanslenacting with said elements; an auxiliary spring resistance coactingwith said means; and bearing members interposed between said elementsand the shoes7 said bearing members having curved bearing surfaces onone side and fiat wedge-acting faces on the other side.

11. In a friction shock absorbing mechanism; the combination with afriction shell; of a` main spring resistance; friction shoes cooperablewith the shell; relatively pivotally mounted wedge elements; adjustablebearing members between said wedge elements and the shoes; awedge-shaped cap, disposed between and cooperating with the inner endsof said wedge elements; and spring means opposing movement of said capinwardly of the mechanism.

1Q. In a friction shock absorbingr mechanism, the combination with afriction shell; of a spring resistance; friction shoes cooperable withthe shell, a pair of pressuretransmitting wedge elements fulcrumedintermediate their ends; adjustable bearing members between saidelements and the members between said wedge elements and the shoes; awedge-shaped spring cap cooperable with the inner ends of said wedgeelements; and an independent spring for said cap.

lll. In a friction shock absorbing mechanism; the combination with afriction shell having interior friction surfaces converged inwardly ofthe shell; of opposedv friction shoes cooperable with the shell, eachshoe having a` concave bearing face on its inner side; a springresistance for said shoes; a pair yof pressure-transmitting wedgeelements fu'lcrumed intermediate their ends; bearing members interposedbetween said elements and the shoes and having curved bearing facescooperable with the curved bearing faces of the shoes; a wedge-shapedspring cap-fitting between and cooperating with the inner ends of saidwedge elements; and an independent spring resistance for said cap.

Inwitness 4"that I claim' the foregoing I have hereunto subscribed myname this 8th day of December, 1922.

ARILD M. BRENNE.

